Cranfield Aerospace Solutions (CAeS) has selected Evolito will provide the electric motor and inverters for its Project Fresson hydrogen-powered aircraft. Under the terms of an agreement announced on April 14. Evolito will contribute to efforts to retrofit twin-engined Britten-Norman Islander aircraft to carry nine passengers on short-haul routes, with the goal of having the first converted models approved in 2025.
UK-based Evolito is joining existing Project Fresson partners including propulsion innovator Reaction Engines, which will provide fuel cell cooling technology to work with the hydrogen fuel cell system being supplied by Ricardo UK and fuel tanks from Innovatus Technologies to contain the gaseous hydrogen. CAeS has longer term plans to scale up the propulsion technology to convert a still-unidentified 19-seat aircraft and eventually airliners carrying as many as 100 passengers.
According to Evolito, its motors are smaller, lighter, and typically four times more power dense than radial flux motors, making them ideally suited to the emerging zero-emissions aviation markets. The company says its axial-flux technology requires up to 75 percent less iron, less copper, and fewer permanent magnets than competing radial solutions, making it lighter and more environmentally friendly.
A radial flux motor generates flux perpendicular to the axis of rotation, while an axial flux motor generates flux parallel to the axis. The flatter shape of the axial flux motor contrasts with oblong-shape radial flux designs, resulting in what the company calls “best-in-class power and torque density.”
For Project Fresson, motor and controller weight represents an important element in the overall mass of the hydrogen-electric propulsion system; less weight maximizes the payload and range that the zero-emissions aircraft can achieve. CAeS maintains the motor also produces efficiency benefits from its novel cooling systems, meaning the unit never overheats and can run on maximum performance settings at all times.
“Evolito’s revolutionary motor isn’t just lighter and more efficient, it’s also an extremely compact solution that has allowed CAeS to integrate and package the technology efficiently, as part of the 240kW Fresson fuel-cell propulsion system that has been packaged within the Islander engine nacelle,” said Evolito director of engineering Rob Marsh.
Backed by venture capital groups B-Flexion and Oxford Science Enterprises, Evolito emerged in July 2021 as a spinoff from a company called YASA to harness aerospace intellectual property before Mercedes-Benz acquired its automotive activities. YASA—which stands for Yokeless and Segmented Armature—achieved prominence in aviation circles through its involvement in Rolls-Royce’s Spirit of Innovation project.
CAeS has announced several provisional sales commitments from companies looking to include the hydrogen-powered Islander in their fleets. These include leasing group Monte and German airline start-up Evia Aero. In August 2022, the group announced it had raised further funding through new investors in the UAE and California.
